The invention pertains to a bus system, with a bus line, to which electronic devices can be connected, wherein at least one electronic device can be connected to the bus line at a separable interface, wherein the interface contains a first and second terminal connection in the motor vehicle, and wherein the first terminal connection is connected to a first section of the bus line and the second terminal connection is connected to a second section of the bus line.
DE 196 24 027 A describes an on-board computer system for machines which comprises a detachable on-board computer with memory, input devices and display devices.
EP 0 203 662 A describes a communication system for transmitting electronic messages between an agricultural machine and a tractor, wherein said communication system contains a bus in the form of a line. Electronic controllers for controlled devices, display devices and sensors are respectively connected to the bus via assigned terminal units. The bus transmits the data in serial form.
Today, bus systems of this type are usually realized in the form of so-called CAN.buses. They contain a continuous bus line, at both ends of which one respective matching resistor is arranged. All controlling and controlled controllers of the connected devices are connected to the bus line. The CAN specification allows only feeders with a length of 1 m between the backbone and the connected devices or controllers. The agricultural interpretation according to ISO 11783 also prescribes feeders with a length of only 1 m. This means that the bus line must extend into the vicinity of the plug of the connected devices or controllers. Consequently, the bus line runs twice in many sections of the wiring, namely from the main cable harness to the device plug and back again.
In instances in which a detachable device should be connected to the bus line, the above-mentioned standard stipulates the utilization of a plug connector, wherein the bus line is cut in the vicinity of the device (e.g., underneath the cabin console) and expanded with a T-shaped wiring arrangement. In this T-shaped wiring arrangement, the bus line extends from the backbone to a second plug connection, to which the device can be connected, via a first plug connection. The bus line then extends from the second plug connection to a third plug connection where it is connected to the backbone again. In order to observe the specifications of the above-mentioned standard with respect to the length of the feeders, the two sections of the bus line must extend through the second plug connection. The connection between the two sections of the bus line is formed by the cable that is connected to the device and must be connected to the plug connection (or in the device). When the device is disconnected, it is necessary to produce a connection between the two sections of the bus line in order to prevent an interruption of the bus line. A suitable plug is provided for this purpose.
In this respect, it is disadvantageous that when connecting and disconnecting the device, the bus line is interrupted during the time in which no plug is located in the plug connection. The bus line is not functional when the device is disconnected and no plug is provided for producing the connection between the sections of the bus line.